IMIKNYLMKTIIYLTRIAZOLE CARBOXVLIC ACID 233 The phenylhydrazine and bydrocbloric acid are mixed together, stirred mechanically and cooled witb a few lumps of ice whilst the nitrite solution is added, until the test with starch- iodide paper shows that an excess is present. The hydro- chloride dissolves, and diazobenzolimidc separates out as an oil. /N C(!n,Nn.NH.,+ nNOo-Cr!I.N< || +2l-I,O \N' Part of the water is removed by a syphon and the oil is extracted with ether ; after removing the ether, the diazobenzol- imide is purified by distillation in steam. l\ is again extracted and separated witb ether as before. Yield, about 25 grams. 4 grms. sodium. 68 c.o. absolute alcohol. 22 grins, acctoacetic ester. 20 Ą diazobcnzolimide. The sodium is dissolved in the alcohol, and to the cold solu- tion a mixture of the acctoacetic ester and diazobenzolimicle is added, and then warmed to boiling with reflux condenser. As soon as this occurs, the tla.sk is removed and cooled, if the action becomes too violent. After the reaction is over, the mixture is heated, for an bour on the water-bath with reflux con- denser, when the contents of the flask become almost solid. The mass is dissolved in the smallest quantity of hot water, and the liquid, if neutral, made strongly alkaline and boiled again for an hour. About 350 r.c. bot water arc added, and sufficient hydro- chloric acid to precipitate the triaxolc carboxylic acid. It is filtered and washed with a little water, and is then nearly pure ; m. p. 155". Yield, about 27 grams. M.C:,,!!,, N.QH, // ' X\ N/ ~r , rHON "N C.CH:i + 2C,HflOH. H/CO.CH,, "h ca"f,ONa..... y ^ N ! " NóC.COONa CIUCOOCUL, See Appendix, p. 320.